1. Field of the Invention
The present invention relates to an image pick-up apparatus for picking up an image of a subject.
2. Description of the Related Art
Hitherto, image pick-up apparatuses for a digital camera and the like comprise color filters which are arranged between two-dimensionally arranged pixels and an image pick-up lens for condensing light from a subject so as to obtain a color image.
FIG. 17 is a schematic diagram of the conventional arrangement of color filters. Herein, a Bayer arrangement is shown. Reference symbols R, G, and B denote a red transmitting filter, a green transmitting filter, and a blue transmitting filter, respectively.
Referring to FIG. 17, an image pick-up operation and an the operation for detecting a focal point is performed by using a signal from the image pick-up apparatus having the arrangement of color filters shown in FIG. 17.
However, in the conventional art, the color filters are arranged to obtain a color image, and therefore the signal level output from each pixel is lower than that in the case of no arrangement of the color filters. More specifically, the signal level with the color filters is approximately ⅓ of that in the case of no arrangement of the color filters.